Process for the preparation of common salt for domestic and other uses.



UNITED STATES GEORGE T. HOLLOWAY,

EN OFFICE? OF LONDON, ENGLAND.

rno'cnss son m m'nranarrou or common sanr FOR norms'rro AND o'rmsn usns.

No. 903,403. Specification of Letters Patent. Patented Oct. 27, 1908.

Appfication filed January 2, 1906. Serial No. 29433.

, LOWAY, a subject of the King of'Great Britain and Ireland, residing at London, England,'(.whose post-office address is 57 and 58 Chancery Lane, London,-W. 0., England,

have invented a certain new and use Process for the Pre aration of Common Salt lized out.

for Domestic and ot er Uses, of which the following is a specification.

This invention realtes to the preparation of common salt so that its tendency to cake on exposure shall be precluded. This caking is, as is well known, due to the presence of the chloride and other deliquescent salts ofcalcium and magnesium, and the present invention consists in coating the prepared anulesfor cyrstals of common saltwith ely powdered carbonate of soda for the purpose of converting the deli uescent chlorid or other com ound" of ca ciuin or magnesium at or near t e surface ofthe. crys- I long been known to add sodium carbonate to the brine-before the common salt is crystal- It is however found that the comparatively pure salt thus roduced still solid state, but to cakes together on keeping. urthermore it is known togrindcommon-salt with carbon- I to the same extent on keeping.

. According to the invention a relatively small uantity of carbonate of soda is used v which y being coated on the prepared crys- .talsior granules effects the conversion of the deliquescent compounds at or near the surface onl Whenhowever the prepared salt is dissolved in water or used as a condiment 4 tation oft e calcium and magnesium sa the solution of the carbonate and common salt takes lace simultaneously and precipits as carbonates is immediate, so that the actual uality of the salt is the same as though the c 'emical reaction had actually taken place during the process of preparation.

ateof so a,- anhydrous carbonate or the bicarbonate or other of the ordinary forms of carbonate, is ground to a fine powder. The salt is ground or rubbed down to a suflicient degree of fineness to pass through an ordinary reasonably fine sieve, say one having about 30 or 40 holes to the linear inch and is then sifted on a 1 sieve having a larger number of holes (71. e; of

T In ca g out'my invention the'carbond which may be either the "normal small aperture) say 100'holes per linear inch,

and the salt which does not pass through such finer sieve, is employed for my process."

Such coarser salt is agitated without grinding, with so much of the finely ground carbonate of soda as is sufficient to precipitate the whole or a proportion of the calcium and magnesium which is present, as carbonate, the agitation being suflicientlynprolon ed to insure that the carbonate shall be we distributed upon and amon the salt particles."

The salt, if damp,: is ried before admix ture with the carbonate as my invention consists in coating the particles with the carbonate and not necessarily in producing any chemical change other than such as takes placefrom mere contact at the surface of'the salt articles.

I d that the theoretical quantity of car bonate of soda or even less, is generall sufficient to produce a non-caking salt" t I find that; with some varieties of salt, it is best to first mix the finely round' carbonate of soda with a which passed t salt which has been still more finely ground (say one art of carbonate by we ht with ten parts y weight of such sa t) be ore mixing it with the coarser salt as this insures a more regular distribution of the carbonate over the salt particles while still leaving the final roduct distinctly gliialnular. v

I End that, with or ary kitchen and proportion o the original salt; rough the fine sieve, or with ,other "commercial salt as sold for domestic. 1

use etc. one part by weight 0t ordinary anhydrouscarbonate of soda is sufficient for the treatment of one hundred parts by weight of the salt. correspondingly more may, however, be used if the proportion of dehquescent calcium and'magnesmm compounds in the salt'exceed the normal amount. The formation of the carbonates of calcium and, magnesium, is, of course coincident with the formation of an equivalent amount of sodium chlorid from the carbonate of soda used so that the final product may be actuallIy thin filmjform coating of finely powdered so 1' richer in sodium chlorid than was the sa dium carbonate. from which it was prepared. In testimony whereof I have hereunto What I claimas my invention 'and desire signed my name to this specification in the to secure by Letters Patent is: presence of two subscribin witnesses.

The process of preparing a table salt which GEORGE HOLLOWAY.

consists in producin a dry granulated body Witnesses:

of salt havlng granu es of substantially um- GEORGE E. HUNT, form size, and coating said granules with'a H. D. IJAMESON. 

